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Discover Which Month in 2020 Hosts a Leap Day
Mastering the Art of Accurately Determining Leap Years
1. The Joyful Calendar
- Calculated based on Earth's orbit around the Sun.
- Includes an extra day in February; in leap years, February has 29 days, while in normal years, it has 28 days.
2. The Leap Lunar Calendar
- Calculated based on the orbit of the Moon around the Earth.
- Adds an additional 13th month, resulting in two identical months.
II. The Most Accurate Leap Year Calculation Method
As mentioned earlier, leap years in the solar and lunar calendars differ, and thus the calculation methods for leap years in the solar and lunar calendars are also different.
1. The Method of Calculating Leap Years in the Gregorian Calendar
How to calculate a leap year in February with 29 days? If it's a leap year in the Gregorian calendar, then that year has February with 29 days (meaning an extra day compared to a regular year). To calculate a leap year in the Gregorian calendar, you just need to divide the year by 4. If it's divisible by 4, then it's a leap year; otherwise, it's not.
Leap year 2020 in the Gregorian calendar
For example:
- Is 2020 a leap year? If you divide 2020 by 4, you'll get 505. Therefore, 2020 is a leap year in the Gregorian calendar, so February of 2020 will have 29 days.
- Leap year 2016? If you divide 2016 by 4, you'll get 504. Therefore, 2016 is a leap year in the Gregorian calendar.
The Following Leap Years in the Gregorian Calendar
2. The Method of Calculating Leap Years in the Lunar Calendar
With the leap year in the lunar calendar, a year will have an additional month, making it 13 months. When the Sun, Moon, and Earth are aligned, meaning the lunar conjunction occurs first. And two lunar conjunctions are approximately 29.5 days apart. Therefore, a complete lunar month will have 30 days, and an incomplete one will have 29 days. Since the lunar calendar starts on the day of the lunar conjunction adjacent to the 'vernal equinox,' the actual deviation per year is 11 days. Thus, after counting 3 years, there will be a surplus of 33 days. Therefore, every 3 years will have a leap year. Then, adding 2 more years will result in 25 days, which equals one leap month. So, in 19 years, there will be about 7 leap months.
Each ordinary month usually has one 'qi' day and one 'jie' day. The average number of 'jie' and 'qi' days will be 30.4 days. Therefore, a lunar month will have 29.5 days. Thus, every 2 to 3 years with a month having only 'jie' days without 'qi' days, people consider that month as a leap month.
To simplify the leap month calculation, you can apply the following method: Divide the number of years in the Gregorian calendar by 19. If the remainder is 0, 3, 6, 9, 11, 14, or 17, then that year in the lunar calendar has a leap month.
For example:
- When dividing 2004 by 19, the remainder is 9, so 2004 is a leap year, and the leap month will be February.
- Dividing 2020 by 19 results in a remainder of 6, so 2020 is a leap year, and the leap month will be April.
The Following Leap Years in the Lunar Calendar
How to Calculate Leap Years in Excel
Besides the method mentioned above, you can use Excel to calculate leap years with the following formula:
III. Is 2020 a leap year in both lunar and solar calendars?
According to the leap year calculation mentioned above, 2020 is a leap year in both the solar and lunar calendars. Therefore, in the solar calendar year 2020, February will have 29 days, while in the lunar calendar, there will be 2 months, specifically 2 Aprils. Thus, the year of Canh Tý 2020 will be longer than other normal years.
Surely, many of you have heard about leap years but not all years are leap years, and some years have it once in a while. To know which year is a leap year and which month is a leap month, you can refer to the most accurate leap year calculation method shared by Mytour above. Additionally, you can also learn about How to Calculate Hours According to the 12 Zodiac Signs here.
